<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>let 命令</title>
 <script>
function add([x, y]) {
console.log(x + y); //30
}
add([10, 20])
</script>
 </head>
 <body></body>
 </html>